The Periodic Table

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Across
  1. 7. what year was the first periodic table created in
  2. 8. who discovered a set of patterns that applies to all elements?
  3. 9. all elements are considered what?
  4. 10. according to what was the first table arranged
Down
  1. 1. tells us the amount of protons/electrons
  2. 2. word for a regular or repeated pattern
  3. 3. a letter or abbreviation to describe an element
  4. 4. what were most of the elements discovered by 1869?
  5. 5. How many elements were discovered by 1869?
  6. 6. mass the average mass of all isotopes of that element